1. Field of the Invention
The present invention relates to a programmable portable infusion pump system for automatically injecting a medicinal substance into a patient, of the type comprising a supply chamber containing the medicinal substance, a pump unit comprising a motor and a pump driven by the motor to inject the medicinal substance into an infusion tube connected to the patient's body, and a programmable controller enabling the motor at instants programmed in advance.
2. Description of Prior Art
It has become more and more common to treat certain diseases by regular intravenous, intra-arterial or intra-rachidian injecting of a medicinal substance. In order to leave the patient with some autonomy and not force him to spend too frequent of stays in hospitals and get the infusions performed on him, portable systems have been realized.
An infusion tube is then available connected to the patient's body so as to perform the infusion when necessary. When the infusion is to be performed, a portable infusion pump system that the patient carries is connected to the infusion needle. Infusion is performed by a pump driven by a motor, the latter pump injecting the medicinal substance coming from a supply chamber into the patient's body thru the infusion tube. The motor, the pump and the supply chamber are integrated in the portable infusion pump system.
Programmable portable infusion pump systems have been realized. In such systems, a controller integrated in the system allows to program the therapeutic protocol i.e. the metering of the infusion to be performed, its duration, and the time when it needs be started. Current systems of this type comprise to this effect a controller which is indeed a simple programming means in that it allows programming of the therapeutic protocol relative to the instant when the system is turned on, but does not allow a programming according to solar time. Besides, programming is usually done thru multifunction keys, which results in limiting the programming possibilities in case there are few keys, or increases possibilities of mistakes in case there are too many functions.
In the majority of current systems, only the supply chamber containing the medicinal substance, also called `cassette`, is removable from the whole system, so as to allow its replacement when it is empty. On the contrary, the pump unit and the controller are made one element, which is a major drawback of the current programmable infusion pump systems.
There also exists programmable portable systems such as the insulin infusion system described in U.S. Pat. No. 4,270,532 in which a unit containing the motor, the pump and the insulin supply chamber is removable from the controller. But this system features two main drawbacks. Indeed it is more and more common to inject several medicinal substances simultaneously to improve the efficiency of a therapeutic treatment. In this case, the patient needs then to get a second portable infusion pump system to allow two simultaneous infusions but still keeping his autonomy without being confined in hospitals. The cost of two portable infusion pump systems becomes then prohibitive, not to mention the difficulty for the patient to carry two infusion pump systems which, even though not heavy, are cumbersome. The second drawback of this system is that the controller becomes autonomous only after having been programmed by an external programming means connected to the controller. This programming therefore requires the patient to go to the hospital where the programming means may be found each time an infusion is required.